1.Field of Invention
The present invention relates to a key structure, and more particularly, the present invention relates to a key structure outputting a signal with a control member through contact members combined with the control member.
2.Related Art
Key structures are required in consumer electronics in daily life and in large industrial processing equipments as the media to control the electronics and processing equipments. Conventional key structures are normally classified into dome switches and rubber switches.
FIG. 1A is a schematic stereogram of a dome switch according to the prior art. A metal dome 11 is disposed on an electric contact 31 of a circuit board 30. When a user presses a key 12, it is pressed against the metal dome 11 so as to be in electrical contact with the electric contact 31 to output a corresponding signal. The key 12 then returns to its original position with the elastic force of the metal dome 11 after the pressure on the key 12 is released.
FIG. 1B is a schematic stereogram of a rubber switch according to the prior art. A plurality of keys 21 is arranged into a module with fixed intervals by a rubber material 20. A conductive rubber 22 is disposed on one end of a key 21 corresponding to an electric contact 31. When the key 21 is pressed, the conductive rubber 22 of the key 21 is in electrical contact with the electric contact 31 to output a corresponding signal. Then the key 21 turns to its original position with the elastic force of the rubber material 20.
As shown in FIG. 1A, the conventional dome switch has to use a transparent thin film 13 to attach the metal dome 11 on the electric contact 31, so as to prevent the situation that the key 12 cannot be in electrical contact with the electric contact 31 through the metal dome 11 as the metal dome 11 leaves the corresponding position of the electric contact 31 due to external force. After having been used for a long time, the functionality of the transparent thin film 13 may get lost because of the deterioration of the material, which leads to lower accuracy during the aligning of the metal dome 11. Furthermore, the application of the transparent thin film 13 incurs additional manufacturing cost.
As shown in FIG. 1B, the rubber module applied in the conventional rubber switch occupies too much space during the assembling, thus the positions for other electronic components are limited, which doesn't comply with the requirements that electronic devices shall be light and thin currently. Furthermore, the rubber material 20 for fabricating the rubber switch module also constitutes a burden to the manufacturers.